标题： 非范德华半金属W5N6的降尺度与电阻率保持 显示英文标题

标题： Downscaling of non van der Waals Semimetallic W5N6 with Resistivity Preservation

摘要： 过渡金属氮化物（TMNs）的体相长期以来一直是广泛研究的对象，由于它们作为涂层材料、电催化剂和扩散屏障的实用性，这归因于它们的高导电性和难熔特性。 将TMNs缩小为二维（2D）形式将为现有的二维材料库提供有价值的成员，并在各种应用中可能带来性能提升。 此外，计算预测了在二维极限下TMNs中可能出现不寻常的物理现象。 在本研究中，我们使用原子替代方法合成了具有可调厚度的二维W5N6，从几十纳米到2.9纳米。 获得的薄片表现出高结晶度和平滑表面。 对15个样品的电气测量显示平均电导率为161.1 S/cm，在厚度从45.6纳米减少到2.9纳米时仍保持不变。 观察到的弱栅极调节效应表明合成的二维W5N6具有半金属特性。 进一步研究转化机制阐明了前驱体中硫属元素空位在引发反应以及应变在传播转化中的关键作用。 我们的工作引入了一种理想的半金属晶体到二维材料库中，并为未来合成设计提供了机理见解。 显示英文摘要

摘要： The bulk phase of transition metal nitrides (TMNs) has long been a subject of extensive investigation due to their utility as coating materials, electrocatalysts, and diffusion barriers, attributed to their high conductivity and refractory properties. Downscaling TMNs into two-dimensional (2D) forms would provide valuable members to the existing 2D materials repertoire, with potential enhancements across various applications. Moreover, calculations have anticipated the emergence of uncommon physical phenomena in TMNs at the 2D limit. In this study, we use the atomic substitution approach to synthesize 2D W5N6 with tunable thicknesses from tens of nanometers down to 2.9 nm. The obtained flakes exhibit high crystallinity and smooth surfaces. Electrical measurements on 15 samples show an average electrical conductivity of 161.1 S/cm, which persists while thickness decreases from 45.6 nm to 2.9 nm. The observed weak gate tuning effect suggests the semimetallic nature of the synthesized 2D W5N6. Further investigation into the conversion mechanism elucidates the crucial role of chalcogen vacancies in the precursor for initiating the reaction and strain in propagating the conversion. Our work introduces a desired semimetallic crystal to the 2D material library with mechanistic insights for future design of the synthesis.